Apparatus for grinding the bottom of drinking glasses

ABSTRACT

The specification describes an apparatus for grinding the bottoms of glasses, more particularly stemmed glasses. The apparatus comprises a grinding wheel, glass holding means capable of being moved in relation to the grinding wheel so as to increase and decrease the distance between them, the glass holding means being capable of being turned about an axis aligned with the direction of relative movement, a yoke, a holding element capable of being moved in the above-mentioned direction in relation to the yoke, the holding element serving for moving the glass in the above-mentioned rotational axis against the yoke leaving the underneath of the glass free.

United States Patent Spaeth et al. 1 Sept. 5, 1972 [54] APPARATUS FOR GRINDING THE 1,559,643 11/1925 Powell .51/105 BOTTOM OF DRINKING GLASSES 1,688,424 10/1928 Kiefer ..51/227 X l 933 373 10/1933 Fraser ..51/l65.9 X [72] Inventors: Claus Spaeth Wadgassen, Saar,

Gunter wuhehn Bous Saar? both of 2,511,563 6/1950 Bullard ..51/ 165.9 X Germany Primary Examiner-Lester M. Swingle [73] Assignee: Villeroy Boch Keramische Werke, I-1 & Stem K.G., Mettlach, Saar, Germany 22 Filed: July 15, 1970 [571 Answer [211 App. No; 55,017 The specification describes an apparatus for grinding the bottoms of glasses, more particularly stemmed glasses. The apparatus comprises a grinding wheel, [52] US. Cl. ..51/105 R, 51/227 glass holding means capable of being moved in rela [51] Illt. CI. ..B24b Il00 tion to the grinding wheel so as to increase and [58] Field Of Search ..51/105 R, 227 R, 165.9 decrease the distance between them h glass holding means being capable of being turned about an axis [56] References Clted aligned with the direction of relative movement, a UNITED STATES PATENTS yoke, a holding element capable ofbeing moved in the above-mentioned direction in relation to the yoke, the Dlnaway element erving for moving the in the 185,227 12/1876 Haley ..51/105 above memioned rotational axis against the yoke lea 398,454 2/ 1889 Schrader ..51/105 ing the underneath of the glass free 625,547 5/1899 Fondu ..51/105 1,223,219 4/1917 Tichbome ..51/227 8 Claims, 5 Drawing Figures Ell PAIENIEB SEP 5 2 SHEU 1 OF 3 IN V EN TORJ' M. 1

BY )Wwhw 4774 war;

PATENTED E 5 9 3 688,448

sum 3 or 3 IN VEN TORJ APPARATUS FOR GRINDING THE BOTTOM OF DRINKING GLASSES BACKGROUND OF INVENTION operation on the undersurface of the bottom of the glasses.

2. Short Summary of Invention An apparatus in accordance with the invention for the grinding of the bottom of drinking glasses, more particularly stemmed drinking glasses, comprises a grinding wheel and a holding means which can be moved in relation to the grinding wheel towards it and away from it. The holding means is arranged to be capable of rotating about an axis aligned with the direction of relative movement. The apparatus further comprises yoke means by means of which theglass to be ground is held in the yoke so as to be aligned with the axis of rotation, the bottom surface of the glass being left free and the yoke engaging the glass. In the case of a form of the apparatus specifically adapted for grinding stemmed glasses the yoke and the holding element have broken away rings placed concentrically about the axis of rotation so as to engage the goblet part and the foot of the stemmed wine glass.

If on the other hand the apparatus is specifically adapted for grinding stemless glass drinking ware such as beakers, the yoke has a ring about its axis of rotation and the holding element is a ram also aligned with the axis of rotation serving for pressing the glass into the ram.

With an apparatus in accordance with the invention it is possible by means of a grinding wheel perpendicular to the glass bottom to produce a satisfactory concave ground surface on the underside of the glass bottom, the periphery of the grinding wheel moving along the glass bottom which is turned about its axis.

In accordance with an advantageous embodiment of the invention the yoke is in the form of a cylinder which is broken away for part of its periphery and on whose one end wall the above-mentioned ring is arranged in which the holding element is arranged. The cylinder is carried on a hollow shaft which has an axially moving shaft extending through it which cannot be rotated in relation to it. One end of the shaft inside the hollow shaft is engaged by a shifting element, preferably a pneumatic cylinder while on the other end the holding element is arranged. Furthermore the above-mentioned hollow shaft is connected in a rigid manner with a pulley driven by a suitable belt.

In the case of an apparatus for the grinding of stemmed glasses the stern of the glass is only subjected to tension to a slight degree; there is no torsional loading of the comparatively brittle stem.

Further measures which may be employed for embodying the invention in a convenient manner will be gathered from the following description of different forms of the invention, and from the claims.

The drawings show two forms of the invention.

LIST OF SEVERAL VIEWS OF THE DRAWINGS FIG. 1 is a cross-section through an apparatus in accordance with the invention for grinding the bottom of stemmed drinking glasses.

FIGS. 2 and 3 are sections on the lines Il--II and III-III of FIG. 1 respectively, the glass being omitted in the first section.

FIG. 4 is a circuit diagram of a hydraulic-pneumatic device for moving a part of the apparatus shown in the figure.

FIG. 5 is a partial view of a modified form of the apparatus in accordance with FIG. 1.

DESCRIPTION OF PREFERRED EMBODIMENTS OF INVENTION Referring now more particularly to FIG. 1 of the drawings it will be seen that the apparatus comprises a machine frame in which a grinding wheel 2 or disc is arranged vertically so as to grind with its periphery. The wheel is driven by means of a V-belt 3 and an electric motor 4.

Furthermore on the machine frame 1 two vertical guide rods 6 are mounted between two short horizontal arms 5. Only one of these guide rods is apparent in the figure. A carriage or slide can be slid along the two guide rods 6 and comprises two plates 7 and 8 and four sliding bushes 9 arranged between these plates. Two bushes are mounted on each guide rod 6.

On the plate 7 of the carriage or slide a bearing housing 11 is attached in which a hollow shaft 14 is journalled in taper roller bearings 12 and 13. On one end of the hollow shaft 14 an annular disc 15 is'mounted. The taper roller bearings 12 and 13 have their outer race rings 16 engaging steps in the bearing housing 11 while the inner race rings 17 are held by a washer l 5" and a nut 18 with peripheral slots screwed on the hollow shaft 14. Accordingly the hollow shaft 14 cannot be axiallymoved in the bearing housing 11. The bearing housing 11 is closed above by a cover 19 which is screwed in position. i

The disc or washer 15 forms the upper end wall of a cylindrical pot 20 whose side wall only extends for about three quarters of the periphery and whose other end wall is formed by an annular disc 21 and a hard PVC (polyvinylchloride) ring 22 inserted in it. Both the disc 21 and the ring 22 have an opening or cut away part open to the same side as the opening in the side wall of the pot (see FIG. 2). On the upper side of the washer 15 or disc a V-belt pulley 23 is arranged which is connected by means of a V-belt, indicated in broken lines, with a further V-belt pulley 24 which is mounted on the drive shaft 25 of a gear ring or transmission 27 connected with a motor 26. The transmission 27 is attached to the plate 8.

The hollow shaft 14 has a shaft28 passing through it which can be moved axially. The shaft 28 is provided with a longitudinal groove 29 into which a key 31 is mounted in the longitudinal groove 30 in the hollow shaft 14 so that the shaft 28 cannot be rotated in relation to the hollow shaft 14. It can be seen from FIG. 3 that between the hollow shaft 14 and the shaft 28 a longitudinally slotted bush is provided. The key 31 passing through the slot of the bush 80 is pressed against the shaft 28 by means of a screw 81 fitted in a thread in the hollow shaft 14, and the bush 80 is held between two securing rings 82.

On the lower end of the shaft 28 a cross head 32 is fixed in position and has two rods 33 screwed into it. The bottom ends of the rods are connected with an annular disc 34. A hard PVC ring 35 is mounted in the annular disc 34. The hard PVC ring 35 and the annular disc 34 are broken away radially in the same manner and in the same direction as the hard PVC ring 22 and the annular disc 21. The upper end of the shaft 28 is connected in a manner allowing relative rotation with the piston rod 36 of a pneumatic cylinder 37 which is mounted by means of a bracket 38 from the plate 7. For this purpose the upper end of the shaft 28 carries a bearing housing 39, screwed in position, carrying ball bearings 40, and a bearing pin 41, screwed on the piston rod 36, is mounted in this bearing housing and is held against axial relative movement by means of a securing ring 42.

A cross beam 43 mounted on the two upper arms carries a hydraulic cylinder 44, whose piston rod 45 is connected with a projection 47 on the plate 7 by means of a fork 46. One of the two lower arms 5 has a setting screw 48 extending through it so as to be vertically aligned with the plate 8, the setting screw being adjustable by a knurled-head nut 49.

As is shown in FIG. 4, the upper end of the hydraulic cylinder 44 is connected via a duct 50 with a reservoir 51 and the lower side of the hydraulic cylinder 44 is connected with a duct 52 leading to a reservoir 53. In the duct 52 there is a setting valve 54 which can be adjusted steplessly to regulate the passage of liquid from the hydraulic cylinder 44 to the reservoir 53 while in the other direction liquid can freely flow owing to the presence of a check valve. The setting valve 54 is bypassed by two ducts 55 and 56. In the bypass duct 55 there is a further setting valve 57 of the same type as the setting valve 54, and a cutoff valve 58, while in the bypassed duct 56 there is only a shut off valve 59. Two reservoirs 51 and 53 are connected via compressed air ducts 60 and 61 with an electropneumatic valve 62, provided with a timing device so as to supply compressed air to the upper parts of the reservoirs; the compressed air feed duct 64, provided with a pressure reducing valve 63, leads from a compressor to the electropneumatic valve 62.

From the compressed air feed duct 64 there branch two pneumatic control ducts 65 and 66 which lead to the shut off valves 58 and 59. The control ducts 65 and 66 are closed by means of valves 67 and 68 respectively which are operated by roller followers. As can be seen from FIG. 1 the valves 67 and 68 are arranged adjacent to the guide rod 6 for the carriage made up of the plates 7 and 8, on the machine frame. The rollers 69 and 70 of the roller followers are arranged to cooperate with a ramped control rod 71 attached to the plate 8. The manner of operation of the apparatus is as follows.

In the starting position the reservoir 53 which is connected with the lower end of the hydraulic cylinder 44 is connected with the compressed air, and the reservoir 51 which is connected with the upper end of the hydraulic cylinder 44 is not under load. The piston of the hydraulic cylinder 44 and thus the above-mentioned slide or carriage with the parts fixed to it thus assumes its upper terminal position. The electric motor 26 is switched off; the cylindrical pot 20 and the parts arranged in it are stationary. The pneumatic cylinder 37 has its upper end pressurized with the pressure of the compressed air so that the annular disc 34 with the hard PVC ring 35 assumes its lower position in the cylindrical pot 20. In this position the hard PVC rings 22 and 35 have a distance between them which does not exceed the length of the stem of a stemmed glass 72. Therefore the stemmed glass 72 can be introduced through the broken away part in the side wall of the cylindrical pot 20 and the broken away parts in the annular discs 21 and 34 and in the hard PVC rings 22 and 35 so that the stemmed glass comes to lie in the center of the hard PVC rings 22 and 35. Following this compressed air is admitted to the lower end of the pneumatic cylinder 37 so that the hard PVC ring 35 is raised and the stemmed glass 72 is held between it and the hard PVC ring 22. The hard PVC rings 35 and 22 are for this purpose adapted in shape to agree with the lower part of the goblet of the glass and the upper side of the foot respectively.

As soon as the stemmed glass 72 is held in place, the motor 26 is switched on so as to cause the cylindrical pct 20 to rotate via the transmission 27 and the V-belt pulleys 24 and 23. The key 31 engaging both the hollow shaft 14 and also the shaft 28 causes the PVC ring 35 to be entrained so that the stem of the stemmed glass 72 is not subjected to any torsional load. The ball bearing 40 makes possible a rotation of the shaft 28 in relation to the stationary pneumatic cylinder 37.

Simultaneously with the switching on of the motor 26 the electropneumatic valve 62 is switched on so that compressed air is passed to the reservoir 51 and compressed air is released from the reservoir 53. The piston of the hydraulic cylinder 44 is moved downwards, the oil in the lower cylinder space now flows both through the duct 52 and also through the two bypassed ducts 55 and 56 back into the reservoir 53. The downward movement of the carriage causes the ramped control rod 71 to operate the rollers 69 and of the roller follower valve 67 and 68 and holds them in the pressed in position. As soon as the control rod 71 releases the roller 70, the roller follower valve 68 interrupts the pneumatic control duct 66 and releases compressed air from the shut off valve 59 so that the latter is closed. The oil from the lower part of the hydraulic cylinder 44 can now only escape through the two setting valves 54 and 57; the speed of lowering of the cylindrical pot 20 with the stemmed glass 72 is now substantially reduced. If the control rod 71 also comes out of engagement with the follower roller 69, the shut off valve 58 is also closed in a similar manner so as to shut off the bypassed duct 55 so that the return of the oil only occurs through the setting valve 54 and the speed of lowering of the stemmed glass 72 is substantially decreased once again. The roller follower valves 67 and 68 are so arranged that the switching over from rapid to medium lowering speed occurs approximately 30 mm before the bottom of the glass engages the grinding wheel 2 and switching over from the medium to the lowest speed of lowering occurs only a small distance before engagement of the glass with the grinding wheel. After the bottom of the stemmed glass 72 has engaged the rotating grinding wheel 2 the rotation of the stemmed glass 72 about the vertical axis causes a concave spherical grinding to take place. The force with which in this operation the stemmed glass 72 is pressed against the grinding wheel 2 can be selected by a suitable selection of the compressed air pressure acting on the reservoir 51, for example 4 to 5 atmospheres gauge. The speed of rotation of the stemmed glass amounts for instance to 18 rpm and the speed of the grinding wheel 2 is between 1,400 and 2,800 rpm in accordance with the diameter of the wheel. The depth of grinding is limited by a setting screw 48 which may be adjusted as desired and which engages the plate 8 of the carriage to terminate downward movement. Grinding is carried out for a further short period of time until a period set provides a timing mechanism coupled with the electropneumatic valve 62 has expired and the electropneumatic valve 62 is switched over again. The cylindrical pot 20 with the stemmed glass 72 now returns in an upward direction again and arrives at its terminal position, stopping being carried out by the use of a suitable terminal switch which causes the opening in the pot 20 always to face the operator for removal of a glass and the insertion of a new glass. n actuation of the pneumatic cylinder 37 in the other direction the hard PVC ring 35 again assumes in its lower position in the pot 20 and the stemmed glass 72 can be removed.

FIG. shows a further embodiment of the invention, that is to say a device for the grinding of glass beakers without a stem. The apparatus is identical to the apparatus shown in FIGS. 1 to 4 apart from the cylindrical pot and the parts arranged in it, and also the control means of the pneumatic cylinder 37. FIG. 5 shows the modified cylindrical pct 20 used in partial view. The bottom of the pot consists of a continuous ring 73, which has a hard PVC ring 74 mounted in it. The ring 74 has an insert ring 75 mounted in it in turn, which is made of a somewhat softer synthetic resin. Stemless glass 76 has the edge of its bottom engaging the hard PVC ring 74 which has its inner edge chamferred in order not to obstruct the grinding wheel 2. The somewhat resilient insert ring 75 centers the glass 76. The glass 76 is pressed against the hard PVC ring 74 by a ram 77. The ram 77 is screwed on the shaft 28 and at its lower end carries a synthetic resin cushion 78. For clamping the glass or beaker the upper end of the pneumatic cylinder 37 is put under pressure, instead of the lower end as is the case with the first embodiment of the invention.

We claim:

1. An apparatus for grinding the bottoms of stemmed glasses, comprising a grinding wheel, glass holding means capable of being moved relative to the grinding wheel in a given direction so as to increase and decrease the distance between them, the glass holding means being capable of being turned about a rotational axis aligned with said given direction of relative movement, said glass holding means comprising a yoke, and a holding element also capable of being moved in said given direction in relation to the yoke for moving the glass along said rotational axis to hold the glass against the yoke leaving the bottom of the glass free to be ground by said grinding wheel, said yoke and said holding element each comprising incomplete rings disposed about said rotational axis, said rings being adapted to li betwee a b a e art an d a foot art of the ass wizen the g ass is eld in position and to press ag inst the foot part.

2. An apparatus in accordance with claim 1 in which the yoke forpart of its surface is cylindrical and on its end wall has the ring arranged on it, and in which the holding element is located.

3. An apparatus in accordance with claim 2 comprising a hollow shaft carrying the yoke, an axially movable shaft arranged to slide in the hollow shaft, translatory drive means arranged to act on the sliding shaft, the holding element being mounted on the other side.

4. An apparatus in accordance with claim 3 comprising a belt pulley connected rigidly with the hollow shaft, and a driven belt passing over the pulley.

5. An apparatus in accordance with claim 1 in which the grinding wheel is arranged for rotation about a stationary horizontal axis and the glass holding means is arranged to be capable of being moved vertically.

6. An apparatus in accordance with claim 1 comprising a hydraulic cylinder for bringing about relative movement between the grinding wheel and the glass holding means, reservoirs connected with supply and return ducts of the hydraulic cylinder, and means for supplying compressed air to the reservoirs.

7. An apparatus in accordance with claim 1 in which the grinding wheel is arranged to grind radially and is aligned perpendicularly in relation to the glass bottom.

8. An apparatus in accordance with claim 1 characterized in that the rings are made of plastics material.

CERTIFICATE OF CORRECTIQN Pate 3,688,448 Dated September 5. 1972 Inventor(s) Claus Spaeth and Gunter Wilhelm It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

[30] Foreign Application Priority Data April 1970 Germany... ..P 2O 16 615.8

Signed and sealed this 13th day of March 1973.,

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents 'ORM PO-IOSO (10-69) USCOMM-DC 60375-1 69 urs. GOVERNMENT PRINTING OFFICE: I969 0-366-334 

1. An apparatus for grinding the bottoms of stemmed glasses, comprising a grinding wheel, glass holding means capable of being moved relative to the grinding wheel in a given direction so as to increase and decrease the distance between them, the glass holding means being capable of being turned about a rotational axis aligned with said given direction of relative movement, said glass holding means comprising a yoke, and a holding element also capable of being moved in said given direction in relation to the yoke for moving the glass along said rotational axis to hold the glass against the yoke leaving the bottom of the glass free to be ground by said grinding wheel, said yoke and said holding element each comprising incomplete rings disposed about said rotational axis, said rings being adapted to lie between a beaker part and a foot part of the glass when the glass is held in position and to press against the foot part.
 2. An apparatus in accordance with claim 1 in which the yoke for part of its surface is cylindrical and on its end wall has the ring arranged on it, and in which the holding element is located.
 3. An apparatus in accordance with claim 2 comprising a hollow shaft carrying the yoke, an axially movable shaft arranged to slide in the hollow shaft, translatory drive means arranged to act on the sliding shaft, the holding element being mounted on the other side.
 4. An apparatus in accordance with claim 3 comprising a belt pulley connected rigidly with the hollow shaft, and a driven belt passing over the pulley.
 5. An apparatus in accordance with claim 1 in which the grinding wheel is arranged for rotation about a stationary horizontal axis and the glass holding means is arranged to be capable of being moved vertically.
 6. An apparatus in accordance with claim 1 comprising a hydraulic cylinder for bringing about relative movement between the grinding wheel and the glass holding means, reservoirs connected with supply and return ducts of the hydraulic cylinder, and means for supplying compressed air to the reservoirs.
 7. An apparatus in accordance with claim 1 in which the grinding wheel is arranged to grind radially and is aligned perpendicularly in relation to the glass bottom.
 8. An apparatus in accordance with claim 1 characterized in that the rings are made of plastics material. 